Guarana, a herbal extract from the seeds of Paullinia cupana Mart. has been evaluated in comparison with caffeine on mouse behaviour in forced swimming and open field tests. Guarana (25 and 50 mg/kg, p.o.) and caffeine (10 and 20 mg/kg, p.o.) each significantly reduced the duration of immobility in the forced swimming test suggesting an antidepressant-like effect in mice. At these doses, neither substance affected ambulation in the open field test. However, a high dose of guarana (100 mg/kg) and caffeine (30 mg/kg) significantly enhanced the locomotor activity in the open field test. Caffeine, but not guarana, could effectively block an adenosine agonist, cyclopentyl adenosine (CPA)-induced increase in swimming immobility suggesting that mechanism(s) other than the adenosinergic mechanism are involved in the antidepressant-like activity of guarana.

The effects of guarana (Paullinia cupana) extract were analyzed in rats on acute gastric lesions induced by ethanol and indomethacin and were compared to those produced by caffeine, a methylxanthine. Guarana (50 and 100 mg/kg p.o.) pretreated animals showed a significant reduction in the severity of gastric lesions induced by absolute ethanol in a manner similar to caffeine (20 and 30 mg/kg p.o.). Against indomethacin-induced gastric ulceration, guarana at a higher dose offered significant protection but caffeine was ineffective at the doses tested. In 4 h pylorus-ligated rats, both guarana and caffeine caused significant diminution in the gastric secretory volume as well as the total acidity. Gastrointestinal transit in mice was not significantly affected by either of these agents. These findings indicate that guarana has a gastroprotective property that needs further elucidation as regards to its mechanism.

RESUMOObjetivos: Tumores testiculares são uma rara condição associada à hiperplasia adrenal congê-nita (HAC) que decorrem da hiperplasia de restos adrenais intratesticulares (HRA), raramente ocorrendo associados a neoplasias malignas. Sua diferenciação histológica com tumores de cé-lulas de Leydig é muito difícil, podendo levar a orquiectomias desnecessárias. O objetivo deste relato foi apresentar esse dilema diagnóstico em um paciente com HAC e tumores testiculares bilaterais. Métodos: Relatou-se o caso de um paciente masculino, 16 anos, com diagnóstico de HAC desde os 3 anos de idade, que apresentava tumorações testiculares endurecidas, indolores e de crescimento lento, sendo encaminhado para orquiectomia bilateral. Resultados: Foi decidido por tratamento conservador com prednisona, havendo significativa diminuição do volume testicular e normalização dos níveis de andrógenos. Conclusão: Este caso demonstra a importância de sempre se considerar a hipótese de HRA intratesticulares no diagnóstico diferencial dos tumores testiculares. A investigação e a conduta devem ser conduzidas de maneira cautelosa para se evitar orquiectomias desnecessárias. Arq Bras Endocrinol Metab. 2009;53(8):1052-8 Descritores Hiperplasia adrenal congênita; tumor testicular; hiperplasia de restos adrenais intratesticulares ABSTRACT Objectives: Testicular tumors are a rare condition associated with congenital adrenal hyperplasia (CAH), originated from intratesticular adrenal rest tumors, and they are rarely associated with malignant tumors. Their histological differentiation from Leydig-cell tumors is quite difficult, which would lead to inappropriate orchiectomies. Thus the objective of this report was to present this diagnostic dilemma. Methods: Reported the case of 16-yr-old boy with previous diagnosis of CAH with bilateral testicular enlargement who was recommended to be submitted to a bilateral orchiectomy. Results: Considering this findings, it was decided to treat conventionally with prednisone with significant reduction of testicular volume, and normalization of androgens levels. Conclusion: This case shows the importance of intratesticular adrenal rest tumors in the differential diagnosis of testicular tumors. Cautious approach during investigation and treatment are recommended to avoid inappropriate orchiectomies.